Heat oil in a wok and sauté onion. Then put green chillies, beans, carrot, curry leaves and let it cook for 10 more minutes. Then put these in the dosa batter. Heat dosa tawa and pour the a ladle full of batter. Pour oil lightly on the sides of the dosa. Close the dosa with a lid for a minute or two. Then flip the dosa . keep it in flame till the other side is cooked. Serve hot with coconut chutney and sambar.